My experience has been almost identical to OP's. The kit I bought is fantastic, great price, the website is decent but their lack of communication and poor customer service is unacceptable. I did eventually have success calling them on the phone, but the only place to find their phone number is the top of your e-mail confirmation, they don't list it anywhere else so for the first week or two I thought I could only contact via e-mail.
It took me about a month to receive a kit that was supposed to be shipped in 1-4 days. Like OP, this was because my parts were backordered, but it took 2.5 weeks, 10 e-mails, 5 "contact us" messages on their website, 10 HBT messages and a couple phone calls before I knew that some parts weren't in stock. They shorted me some parts and 2 weeks later I'm still waiting for the correct fittings to arrive (should come in today though).
When my order finally arrived it was in a huge box that was almost ripped in half. The corneys were just sitting there unprotected, and my new CO2 tank was only protected by a thin layer of plastic. Pretty crappy packing of you ask me. I should also mention that all the corneys were pressurized when I received them, this is pretty dangerous, especially since I had it shipped to my work and was going to leave them in my hot car for the afternoon before I noticed this. Again, not acceptable.
I picked Fedex Commercial as the shipping method and they shipped it Fedex Home. This delayed things a couple days, we have a Fedex dude that's at my work a few times a day but the Fedex Home guy tried to come outside business hours and then they waited a few days before they tried again.
Not communicating with someone that just gave you $700 is unforgivable in my book. These guys told me they're real busy setting up a new shop, working out of a warehouse, moving, etc. but if that's the case they should stop accepting new orders until they get their **** together and are back on track. Instead of doing this, they have a gigantic sale giving 5% off coupons away like candy. If you can't fulfill the orders of existing, paid, waiting customers, it's not cool to invite a zillion new orders.
They responded to every request for a coupon within a few hours, but it took 2 weeks to respond to my 20 requests to get my order status. They say it's an e-mail problem on their end, but for a store that's exclusively web-based you'd think they'd make it a priority to fix such a thing.
In conclusion, I'm very happy with the product, assembly, quality etc. but I'm appalled at the customer service. Consider this before you order.